I've compiled the code and tried running it but i still receive a error.

Question

import javax.swing.*;

public class Array {
public static void main(String [] arg) {
String namn;
String hälsning;

namn = JOptionPane.showInputDialog ("Vad heter du");

hälsning = "Välkommen" + namn;

JOptionPane.showMessageDialog(null, hälsning);
}
}

//error message is as the following

Exception in thread "main" java.awt.HeadlessException:
No X11 DISPLAY variable was set, but this program performed an operation which requires it.
at java.awt.GraphicsEnvironment.checkHeadless(GraphicsEnvironment.java:204)
at java.awt.Window.<init>(Window.java:536)
at java.awt.Frame.<init>(Frame.java:420)
at java.awt.Frame.<init>(Frame.java:385)
at javax.swing.SwingUtilities$SharedOwnerFrame.<init>(SwingUtilities.java:1763)
at javax.swing.SwingUtilities.getSharedOwnerFrame(SwingUtilities.java:1838)
at javax.swing.JOptionPane.getRootFrame(JOptionPane.java:1696)
at javax.swing.JOptionPane.showInputDialog(JOptionPane.java:576)
at javax.swing.JOptionPane.showInputDialog(JOptionPane.java:524)
at javax.swing.JOptionPane.showInputDialog(JOptionPane.java:474)
at javax.swing.JOptionPane.showInputDialog(JOptionPane.java:440)
at himynameis.main(himynameis.java:8)

//using Codeanywhere.

Answer 1

If you tried this in Sololearn Code Playground then No GUI frameworks are supported in the Sololearn Code Playground. So you might be getting the errors.

Answer 2

thinking i should maybe change
JOptionPane.showMessageDialog(null, hälsning);

to System.out.print("Vad heter du");